Sulfur spray gun



March 9, 1965 K. M. BARCLAY ETAL 3,172,735

SULFUR SPRAY GUN Filed May 28, 1962 'I'IIIIIIIII KENNETH M.BARCLAY HARRY G.BOCCKINO INVENTORS AGENT United States latent O 3,172,735 SULFUR SPRAY GUN Kenneth M. Barclay, Stockton, and Harry G. Bocckino, Somerville, Ni, assignors to Chemical Construction Corporation, New York, N.Y., a corporation of Delaware Filed May 28, 1962, Ser. No. 198,000 8 Claims. (Cl. 23-278) This invention relates to an improved apparatus for the spray burning of sulfur. An apparatus combination has been developed, which accomplishes a fine dispersion of sulfur droplets in air or other dispersion gas prior to complete combustion. As a result, complete and uniform sulfur combustion is attained using much smaller furnace volume.

The combustion of sulfur to produce sulfur dioxide is carried out in practice by spraying molten sulfur into a brick-lined furnace. An elevated temperature is maintained in the furnace, and combustion air is admitted in the required proportion to permit complete oxidation of sulfur to sulfur dioxide. The sulfur is sprayed into the furnace through one or more sulfur spray burners. Typical spray burners of the prior art are shown in US Patents 1,844,653 and 1,917,692. The sulfur spray generated by such units is typically in the form of relatively coarse droplets. A considerable amount of combustion space is thus required to achieve complete combustion. In general, one cubic foot of space is provided for every 15,000 B.t.u./hr. of heat released. Thus massive and expensive furnaces are required for sulfur burning.

In the present invention, an improved burner apparatus has been devised, which permits the combustion of sulfur using considerably smaller furnace volumes per unit rate of sulfur combustion. This result is achieved primarily because the improved apparatus of the present invention achieves a much finer and more uniform dispersion of sulfur droplets in a dispersion gas which is also passed through the burner. This dispersion gas preferably consists of compressed air, however, due to rapid flow velocities in the burner essentially no combustion of sulfur takes place until the spray is released into the furnace. The burner apparatus essentially consists of an inner conduit terminating at a primary constricting orifice, a central guide rod coaxially aligned within the inner conduit, an outer enclosing coaxial conduit, and a secondary constricting orifice at the end of the outer conduit. A first spiral threading is mounted in the inner annular space between the rod and the inner conduit, and a second spiral threading is mounted in the outer annular space between the inner conduit and the outer conduit. Molten sulfur is passed through the inner annular space and dispersion gas is passed through the outer annular space. These fluid streams are whirled by respective spiral threadings, and due to the action of the orifices an extremely fine and uniform spray of sulfur is produced. The sulfur is thus readily and uniformly burned in a considerably smaller furnace volume.

It is an object of the present invention to provide an improved sulfur spray burner.

Another object is to burn sulfur in an improved manner.

A further object is to burn sulfur using smaller furnace volume per unit rate of sulfur combustion.

An additional object is to more uniformly disperse latented Mar. 9, 1965 molten sulfur into a furnace in the form of finer droplets.

These and other objects and advantages of the present invention will become evident from the description which follows. Referring to the figure, a preferred embodiment of the apparatus of the present invention is presented. The outer enclosing conduit 1 is attached to support flange 2, which in turn is fastened to the furnace wall 3 by means not shown. An inner conduit 4 is coaxially disposed within conduit 1, and a central guide rod 5 is centrally aligned coaxially within conduit 4. A first spiral threading 6 is preferably disposed Within the annular space between rod 5 and conduit 4, by mounting threading 6 on rod 5. It will be understood that the function of threading 6 may also be carried out by mounting a spiral threading or flighting on the inner surface of conduit 4. A tapered conical orifice 7 is provided at the open end of conduit 4, and serves together with the end of rod 5 to restrict fluid flow. It will be appreciated that in practice orifice 7 will preferably be conical, however, other orifice shapes such as a conventional vertical orifice may be employed.

A second spiral threading 8 is preferably disposed within the annular space between conduits 4 and l, by mounting threading 8 on the outer surface of conduit 4. As was the case with threading 6, the function of threading 8 may also be carried out by mounting a spiral threading or flighting on the inner surface of conduit 1. A tapered conical orifice 9 extends from the open end of conduit 1, terminating adjacent to the end of orifice 7. Orifice 9 thus serves to restrict fluid flow in the annular space between conduits 4 and 1, and indirectly also restricts the flow out of orifice 7. It will be understood that, in practice, orifice 9 will preferably be conical, however, other orifice shapes such as a conventional vertical orifice may be employed.

A deflector button 10 is preferably provided at the outlet of orifice 9, and is mounted in place by support rods 11. The function of button It is to deflect fluid flow outwards to form a hollow cone spray, however, in some instances button it) may be omitted. A layer 12 of suitable ceramic insulating material is provided on the inner surface of button 10, to protect the button from overheating due to radiant heat.

Referring now to the section of the spray burner external to the furnace, conduit 4 is supported by suitable mounting such as adjustable support rings 13 and 14, between which gasket 15 is provided. Dispersion gas stream 16 is passed into the annular space between conduits 4 and 1 via flanged inlet 17. As mentioned supra, stream 16 preferably consists of air.

Guide rod 5 is centrally supported by a suitable mounting such as adjustable support ring 18 which cooperates with seal gasket 19. Molten sulfur stream 2th is passed into the annular space between rod 5 and conduit 4 via flanged inlet 21. A suitable steam jacket, not shown, may be disposed about inlet 21 and the outer end of conduit 4, to prevent the solidification of molten sulfur.

In actual operation, molten sulfur stream 20 passes through the annular space between rod 5 and conduit 4, and is given a rotary motion by spiral threading 6. Stream 20 next issues from the opening in orifice 7 as a spray of droplets. The air stream 16 passes through the annular space between conduits 4 and 1, and is given a rotary motion by spiral threading 8. This motion is preferably in the same sense or direction of rotation as the rotary motion of stream 2%. Stream 16 is now accelerated by orifice 9, and suddenly mixes with the droplets of molten sulfur. A uniform dispersion of fine sulfur droplets in the stream 16 thus is obtained. The resulting mixed fluid stream is preferably deflected into a hollow cone path by ellipsoidal button 10, however, if stream 16 is provided with sufficient pressure an adequate dispersion takes place and button it) may be omitted. In this case the furnace will be relatively longer and narrower, and it will be of greater total volume. In any case, the resulting mixed fluid stream mixes readily and evenly with incoming combustion air. In pilot plant tests employing tangential injection of secondary air, liquid sulfur was burned at a heat release rate of 250,000 B.t.u./hr./ft. of furnace volume, with 99.8% of the sulfur being consumed. As mentioned supra, typical conventional sulfur furnaces of the prior art are designed for a heat release of 15,000 B.t.u./hr./ft.

It will be apparent that blockages of orifice members 7 and 9 may be readily relieved in practice. To unplug or rod out orifice 7, ring 18, which constitutes an adjustable support for rod 5, is loosened sufiiciently to permit movement of rod 5. Rod is thus moved forward into the opening of orifice 7, and any solid material causing blockage is thus removed. Orifice 9 is cleaned out in a somewhat similar manner. Ring 13, which constitutes an adjustable support for conduit 4, is loosened sufilciently to permit movement of conduit 4. Conduit 4 is then moved forward and the end of conical orifice 7 passes into the opening of orifice 9. Any solid material causing blockage is thus dislodged and removed.

Various modifications in the apparatus of the present invention will occur to those skilled in the art. Thus, deflector button 10 may be provided with a conical or oval deflection surface, however, an ellipsoidal shape is preferred.

We claim:

1. Sulfur spray burner comprising, in combination, a central guide rod, an inner conduit coaxially aligned with said rod, 2. first spiral threading mounted in the annular space between said rod and said inner conduit, means to pass liquid sulfur in the annular space between said rod and said inner conduit, whereby said liquid sulfur is provided with a whirling rotary motion by contact with said first spiral threading, an inner orifice member extending inwards from the terminus of said inner conduit to a location adjacent to the end of said rod, whereby said liquid sulfur is discharged from the opening in said inner orifice member as a liquid sulfur spray, an outer conduit coaxially aligned with said rod, a second spiral threading disposed in the annular space between said inner conduit and said outer conduit, means to pass a sulfur dispersion gas in the annular space between said inner conduit and said outer conduit, whereby said sulfur dispersion gas is provided with a whirling rotary motion by contact with said second spiral threading, and an outer orifice member extending inwards from the terminus of said outer conduit, said outer orifice member being displaced from said inner orifice member in the direction of liquid'sulfur flow, whereby said liquid sulfur spray discharged from said inner orifice member is contacted with said sulfur dispersion gas between said inner orifice member and said outer orifice member and a mixed fluid stream comprising sulfur droplets finely dispersed in the sulfur dis persion gas is discharged through said outer orifice member.

2. Apparatus of claim 1, in which said orifice members are conical.

3. Apparatus of claim 1, in which a deflector button is axially mounted external to said outer orifice member, whereby the mixed fluid stream is deflected into a conical flow path.

4. Apparatus of claim 3, in which said deflector button is ellipsoidal.

5. Apparatus of claim 1, in which said first spiral threading has a direction of rotation which is the same as said second spiral threading, whereby the molten sulfur and the dispersion gas are whirled and rotate in the same directions prior to mixing.

6. Sulfur spray burner comprising, in combination, a central guide rod, an inner conduit coaxially aligned with said rod, a first spiral threading mounted on said rod in the annular space between said rod and said inner conduit, means to pass liquid sulfur in the annular space between said rod and said inner conduit, whereby said liquid sulfur is provided with a whirling rotary motion by contact with said first spiral threading, an inner conical orifice member extending inwards from the terminus of said inner conduit to a location adjacent to the end of said rod, whereby said liquid sulfur is discharged from the opening in said inner conical orifice member as a liquid sulfur spray, an outer conduit coaxially aligned with said rod, a second spiral threading mounted on the outer surface of said inner conduit and disposed in the annular space between said inner conduit and said outer conduit, means to pass air in the annular space between said inner conduit and said outer conduit, whereby said air is provided with a whirling rotary motion by contact with said second spiral threading, an outer conical orifice member extending inwards from the terminus of said outer conduit, said outer conical orifice member being displaced from said inner conical orifice member in the direction of liquid sulfur flow, whereby said liquid sulfur spray discharged from said inner conical orifice member is contacted with said sulfur dispersion gas between said inner conical orifice member and said outer conical orifice member, and an opposedly faced ellipsoidal deflector button axially mounted external to said outer orifice member, whereby a mixed fluid stream comprising sulfur droplets finely dispersed in air is discharged from between said outer orifice member and said deflector button.

7. Apparatus of claim 6, in which said first spiral threading has a direction of rotation which is the same as said second spiral threading, whereby the molten sulfur and the air are whirled and rotate in the same directions prior to mixing.

8. Sulfur spray burner comprising, in combination, a central guide rod, an inner conduit coaxially aligned with said rod, a first spiral threading mounted on said rod in the annular space between said rod and said inner conduit, means to pass liquid sulfur in the annular space between said rod and said inner conduit, whereby said liquid sulfur is provided with a whirling rotary motion by Contact with said first spiral threading, an inner conical orifice member extending inwards from the terminus of said inner conduit to a location adjacent to the end of said rod, whereby said liquid sulfur is discharged from the opening in said inner conical orifice member as a liquid sulfur spray, an outer conduit coaxially aligned with said rod, a second spiral threading mounted on the outer surface of said inner conduit and disposed in the annular space between said inner conduit and said outer conduit, means to pass air in the annular space between said inner conduit and said outer conduit, whereby said air is provided with a whirling rotary motion by contact with said second spiral threading, an outer conical orifice member extending inwards from the terminus of said outer conduit, said outer conical orifice member being displaced from said inner conical orifice member in the direction. of liquid sulfur flow, whereby said liquid sulfur spray discharged from said inner conical orifice member is contacted with said sulfur dispersion gas between said inner conical orifice member and said outer conical orifice member, an adjustable support for said inner conduit whereby said inner conduit is axially movable relative to said outer conduit, an adjustable support for said central guide rod whereby said rod is axially movable relative to said inner conduit, and an ellipsoidal deflector button axially mounted external to said outer orifice member and opposedly faced relative to said outer orifice member,

5 6 whereby a mixed fluid stream comprising sulfur droplets 1,917,692 7/33 Bencowitz 23278 finely dispersed in air is discharged from between Said 2,072,375 3/37 McCallum 231 outer orifice member and said deflector button. 2,592,297 4/52 Laguilharre 239-404 2,906,234 9/59 Scholz 15877 X References Cited by the Examiner 5 3,024,045 3/62 01691111181121! et a1. 239-404 X UNITED STATES PATENTS FOREIGN PATENTS 1,500,103 7/24 Burdon et a1. 158-73 ,939 1/ 61 Great Britain. 1,564,064 12/25 Hannah 158*73 MORRIS O. WOLK, Primary Examiner 1,844,653 2/32 Hechenblelkner 23278X 10 M AURICE A. BRINDISI Examiner 

1. SULFUR SPRAY BURNER COMPRISING, IN COMBINATION, A CENTRAL GUIDE ROD, AN INNER CONDUIT COAXIALLY ALIGNED WITH SAID ROD, A FIRST SPIRAL THREADING MOUNTED IN THE ANNULAR SPACE BETWEEN SAID ROD AND SAID INNER CONDUIT, MEANS TO PASS LIQUID SULFUR IN THE ANNULAR SPACE BETWEEN SAID ROD AND SAID INNER CONDUIT, WHEREBY SAID LIQUID SULFUR IS PROVIDED WITH A WHIRLING ROTARY MOTION BY CONTACT WITH SAID FIRST SPIRAL THREADING, AN INNER ORIFICE MEMBER EXTENDING INWARDS FROM THE TERMINUS OF SAID INNER CONDUIT TO A LOCATIN ADJACENT TO THE END OF SAID ROD, WHEREBY SAID LIQUID SULFUR IS DISCHARGED FROM THE OPENING IN SAID INNER ORIFICE MEMBER AS A LIQUID SULFUR SPRAY, AN OUTER CONDUIT COAXIALLY ALIGED WITH SAID ROD, A SECOND SPIRAL THREADING DISPOSED IN THE ANNUAL SPACE BETWEEN SAID INNER CONDDUIT AND SAID OUTER CONDUIT, MEANS TO PASS A SULFUR DISPERSION GAS IN THE ANNULAR SPACE BETWEEN SAID INNER CONDUIT AND SAID OUTER CONDUIT, WHEREBY SAID SULFUR DISPERSION GAS IS PROVIDED WITH A WHIRLING ROTARY MOTION BY CONTACT WITH SAID SECOND SPIRAL THREADING, AND AN OUTER ORIFICE MEMBER EXTENDING INWARDS FROM THE TERMINUS OF SAID OUTER CONDUIT, SAID OUTER ORIFICE MEMBER BEING DISPLACED FROM SAID INNER ORIFICE MEMBER IN THE DIRECTION OF LIQUID SULFUR FLOW, WHEREBY SAID LIQUID SULFUR SPRAY DISCHARGED FROM SAID INNER ORIFICE MEMBER IS CONTACTED WITH SAID SULFUR DISPERSION GAS BETWEEN SAID INNER ORIFICE MEMBER AND SAID OUTER ORIFICE MEMBER AND A MIXED FLUID STREAM COMPRISING SULFUR DROPLETS FINELY DISPERSED IN THE SULFUR DISPERSION GAS IS DISCHARGED THROUGH SAID OUTER ORIFICE MEMBER. 